Question: Which of the following ordered pairs represents a solution to the equation below? $(-2, 5) (-1, 2) (0, -2) (1, -3) (2, -9)$ $y = -3x-2$
Solution: We can try plugging in the x-value of each ordered pair into the equation. If we evaluate and get the y-value of the ordered pair, then that ordered pair is a solution! Let's consider $(-2, 5)$ If we plug in $-2$ for $x$ and evaluate, do we get $5$ $y = (-3)(-2) - 2 = 6 - 2 = 4$ Let's consider $(-1, 2)$ If we plug in $-1$ for $x$ and evaluate, do we get $2$ $y = (-3)(-1) - 2 = 3 - 2 = 1$ Let's consider $(0, -2)$ If we plug in $0$ for $x$ and evaluate, do we get $-2$ $y = (-3)(0) - 2 = 0 - 2 = -2$ Let's consider $(1, -3)$ If we plug in $1$ for $x$ and evaluate, do we get $-3$ $y = (-3)(1) - 2 = -3 - 2 = -5$ Let's consider $(2, -9)$ If we plug in $2$ for $x$ and evaluate, do we get $-9$ $y = (-3)(2) - 2 = -6 - 2 = -8$ Thus the only ordered pair that is a solution to the equation is $(0, -2)$ We come to the same answer by plotting the points and the equation. $2$ $4$ $6$ $8$ $\llap{-}4$ $\llap{-}6$ $\llap{-}8$ $2$ $4$ $6$ $8$ $\llap{-}4$ $\llap{-}6$ $\llap{-}8$